【作者】 朱云；

【导师】 陈刚； 雷韦锁；

【作者基本信息】 西安理工大学 ， 水力学及河流动力学， 2003， 硕士

【摘要】 长期以来，黄河宁夏段河道基本处于自然状态，主流摆动频繁，防洪问题突出，影响了当地经济发展和社会的稳定。1998年以来，国家加大投入力度，加强河道治理，但由于缺乏对该段河道的系统研究，工程建设中了出现了一些问题无法解决。因此，开展黄河宁夏段河道整治研究显得十分迫切而重要。 黄河宁夏段属黄河上游下段，全长397km，重点治理的平原河道长266.7km，根据其特性可分为三段。其中下河沿至仁存渡河段为非稳定性分汊型河道；仁存渡至头道墩河段为弯曲型河道；头道墩至石嘴山河段为游荡型河道。河道床质也不相同，仁存渡以上河段为沙卵石，以下河段为沙质。为了探索适宜黄河宁夏段河道特性和演变规律的整治方案、工程布局、工程措施及有关参数，解决实践中存在的问题，进一步开展黄河宁夏段河道整治研究，为今后的工程建设提供理论依据。 河道整治方案是在整治原则的指导下，根据河道特性和演变规律，综合考虑国民经济各部门的要求，结合经济水平而研究确定的。本文根据分汊型河道河床演变特点，通过分析已建工程的效果，总结经验教训，提出了下河沿至仁存渡河段宜采用“工程导送为主，塞支强干、挖引疏浚为辅，多种措施相结合”的整治方案。同时，提出了仁存渡至石嘴山河段适宜采用微弯整治的方案。造床流量是对塑造河床形态所起作用比较大的流量级，是河道规划设计首先必须确定的参数。本文在对平 西安理工大学工程硕士专业学位论文 滩流量法、输沙能力法、输沙量法。挟沙能力法等计算方法进行分析的基础上，结 合宁夏实际情况，提出了造床流量，进而确定了黄河宁夏段的整治流量，下河沿至 青铜峡河段为 2500m’／s，青铜峡至石嘴山河段为 2200m’／s。通过模型试验验证，确 定了宁夏段河湾半径最大为4450m，最小为1450m，平均为3206m。中心角最大为 96”，最个为 36丫平均为 64·9“。经过理论计算和模型试验观测，提出了仁存渡以／．“飞下7y质河床，T坝最大冲刷坑7k深为10～13m，个别受主流持续顶仲的丁坝，最大 Yi 冲刷坑水深可达20m。根据整治方案，结合实际情况，提出了工程布局的原则以及 坝垛形式、坝长、坝间距、坝轴线与主流的夹角等具体参数。推荐了网罩护根防冲 和混凝土四脚体护脚这两种比较有效的护根措施。以上研究，既可为黄河宁夏段治 理提供理论支撑，又可为进一步优化工程设计方案提供帮助指导。更多还原

【Abstract】 The Ningxia reach of the Yellow River is historically natural status and its main channel sways frequently. Flood control becomes an important problem that limits development of local economy and society. The government has invested much in reconstruction of the Ningxia reach since 1998, but many problems appeared in the reconstruction process. Therefore, it is rather necessary to study the problems related to reconstruction of the Ningxia reach.The Ningxia reach of the Yellow River is 397 km long, and the main reconstruction reach located in plain region is 266.7 km long, which is divided into three reaches: the first is unsteady biforked channel between Xiayanhe and Rencundu, the second is bend-type channel between Rencundu and Toudaodun, and the third sway-type channel between Toudaodun and Shizuishan. The upperstream bed of Rencundu is consist of cobblestones and gravels, and the downstream bed of Rencundu is consist of sand.River reconstruction scheme is determined based on reconstruction guidance, river features, evolution tendency, economic level, etc. By analyzing river evolution features, this paper proposes a reconstruction scheme: mainly guiding flow by engineering constaiction, properly strengthening main channel and weakening sub-channels, andcombining other assistant methods. It is shown that a slightly-bending reconstruction scheme is suitable for the reach between Rencundu and Shizuishan. By comparing several calculating methods, the following reconstruction flow rates are proposed: 2500 m3/s for the reach between Xiayanhe and Qingtongxia, and 2200 m3/s for the reach between Qingtongxia and Xiayanhe. Modelling tests show that largest radius of the river bend along the Ningxia reach is 4450 m, smallest radius is 1450 m, averaged radius is ’, 3206 m, largest central angle is 96? smallest central angle 36?and an averaged angle 64.9? Theoretical calculation and modeling test show that depths of scoured pit near the T-type dam may reach -10-13 m for the downstream of Rencundu with sand bed. For thedeepest case, largest scoured pit depth may reach 20 m. Based on the present research result, some detailed measures and methods of reconstruction are proposed.更多还原